Turf Aerator

ABSTRACT

A safety mechanism for a turf aerator having a frame and an engine with a governor that generally prevents the turf aerator from operating at full power unless the safety mechanism is engaged. A blocking mechanism and a manual actuation device are mounted to the frame. The manual actuation device is in mechanical communication with the blocking mechanism. The blocking mechanism urges the governor toward a loaded position and the engine operates at a generally low power when the governor is in the loaded position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is a divisional of U.S. patent application Ser.No. 11/017,294, filed Dec. 20, 2004, which is a continuation of U.S.Pat. No. 7,100,702, issued Sep. 5, 2006.

BACKGROUND OF THE INVENTION

The present application is directed to a turf aerator and morespecifically to an aerator having three separate shafts in axialalignment with each other with the tine assemblies on the middle shaftbeing mounted for free wheel rotation and the tine assemblies on theleft and right shafts being mounted for rotation with the left and tightshafts which may be selectively driven or simultaneously driven.

Core-type aerators are well known in the art and are generally comprisedof a walk-behind unit having a main frame with an internal combustionengine mounted on the top thereof. A transverse shaft is rotatablymounted adjacent a lower rear portion of the frame and has plurality ofdiscs secured thereto which in turn support a plurality of radiallyextending core tines. A suitable drive arrangement is provided betweenthe output shaft of the motor and the tine carrying shaft. A pair ofadjustable wheels are pivotally mounted on opposite sides of the frameadjacent the rear thereof which may be adjustable in height under thecontrol of an operator walking behind the aerator. Suitable controls areprovided on the handle for controlling the drive to the shaft carryingthe care tines. In most models of turf aerators, all of the tinecarrying discs are simultaneously rotated since they are mounted on asingle transverse shaft to which the drive is imparted. At least oneturf aerator model is provided wherein the outermost tine carrying discsare mounted on the shaft for a free wheeling operation

The aerator disclosed in U.S. Pat. No. 6,102,129 is of the walk behindtype and is provided with two independent tine carrying shafts which areaxially aligned with each other for independent rotation relative toeach other. Each shaft is selectively connected to an output shaft of amotor mounted on the frame of the aerator by two separate drive trains,each having a clutch arrangement therein. A pair of control levers ismounted on a handle assembly for operating the clutches in each drivetrain. Thus either or both of the tine carrying shafts may be rotated tofacilitate a turning operation of the aerator or while traversing asloping surface.

The aerator disclosed in U.S. Pat. No. 5,680,903 is provided with aseries of tine assemblies spaced along a driven shaft driven by a motor.Each tine assembly has a plurality of tines for aeration extending in asubstantially radial pattern about the driven shaft. The inner tineassemblies along the middle portion of the driven shaft are secured tothe driven shaft to drive the aerator along the lawn as the driven shaftrotates. The outer tine assemblies adjacent the ends of the driven shaftare rotatably mounted on the driven shaft. This permits the outer tineassemblies to free wheel independently and thereby make the aerator moremaneuverable and easier to turn.

SUMMARY OF THE INVENTION

The present invention provides an improved turf aerator having threeseparate shafts in axial alignment with each other with the tineassemblies on the middle shaft being mounted for free-will rotation andthe tine assemblies on the left and Might shafts mounted for rotationwith the shafts which may be selectively or simultaneously driven. Theturf aerator is provided with a platform upon which the operator willstand to operate the turf aerator. An internal combustion engine isoperatively connected to two hydraulic pumps which in turn are connectedto left and right hydraulic motors respectively, which will impact adrive to the left and right tine carrying shafts respectively. Thehydraulic motors also provide a drive for the left and right main wheelsof the turf aerator respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofpreferred embodiment of the present invention, will be better understoodwhen read in conjunction with the appended drawings. For the purpose ofillustrating the preferred turf aerator of the present invention, thereis shown in the drawings, an embodiment which is presently preferred. Itshould be understood, however, that the invention is not limited to theprecise arrangements and instrumentalities shown. In the drawings:

FIG. 1 is a top perspective view of the preferred turf aerator of thepresent invention;

FIG. 2 is a bottom plan view of the turf aerator of FIG. 1, showing therelationship of time carrying shafts relative to drive wheels;

FIG. 3 is a partially exploded, perspective view of the turf aerator ofFIG. 1;

FIG. 4 is a front perspective view of a tine assembly of the turfaerator of FIG. 1;

FIG. 5 is a schematic diagram of hydraulic circuitry of the turf aeratorof FIG. 1;

FIG. 6 is schematic block diagram of an engine, governor and throttlelever of the turf aerator of FIG. 1;

FIG. 7 is a partial left-side elevational view of the turf aerator ofFIG. 1;

FIG. 7A is a magnifies left-side perspective view of the turf aerator ofFIG. 1, showing a preferred blocking mechanism of the turf aerator; and

FIG. 7B is a magnified left-side perspective view of the turf aerator ofFIG. 1, showing the blocking mechanism of the turf aerator.

DETAILED DESCRIPTION OF THE INVENTION

Certain terminology is used in the following description for convenienceonly and is not limiting. The words “right”, “left”, “lower” and “upper”designate directions in the drawings to which reference is made. Thewords “inwardly” and “outwardly” refer to directions toward and awayfrom, respectively, the geometric center of the turf aerator anddesignated parts thereof. The terminology includes the above-listedwords, derivatives thereof and words of similar import.

Referring to the drawings in detail, wherein like numerals indicate likeelements throughout, there is shown in FIGS. 1-7B, a preferredembodiment of a turf aerator, generally designated 10, for aeratingturf, or, specifically, a lawn. Referring to FIGS. 1-4, the turf aerator10 includes a main frame 12 having an internal combustion engine 14mounted on an upper portion thereof. The main frame 12 is supported by apair of rotatable driven wheels 16, two smaller non-driven wheels 18 onthe rear position of the frame 12 and two even smaller non-driven wheels20 mounted on the front portion of the frame 12. The two smallernon-driven wheels 18 can be raised and lowered by a lever 22 tostabilize; the aerator 10.

A platform 24 for the operator is mounted on the frame 12 substantiallybetween the driven wheels 16 and the rear non-driven wheels 18, as bestseen in FIG. 2. A manual actuation device 26 is mounted at the forwardside of the platform 24 away from the front of the turf aerator 10 and atine assembly 58. The manual actuation device 26 is typically comprisedof a treadle or a foot pedal 26 that is pivotally mounted to theplatform 24. When the treadle 26 is depressed by the operator, theengine 14 can be controlled by the throttle lever 25. When the treadle26 is not depressed, the engine 14 can only operate to idle speedregardless of the operation of the throttle lever 25. Accordingly, theoperator is behind the turf aerator 10 and generally is unable tocontact the tine assembly 58 when the turf aerator 10 is operating orworking when the tine assembly 58 is rotating.

Referring to FIGS. 1, 3, and 6-7B, the treadle 26 provides a safetyfeature for the turf aerator 10 in that the engine 14 will operate atidle or low power unless the treadle 26 is depressed by the operator andthe turf aerator 10 will generally not move or operate unless thetreadle 26 is depressed. Therefore, when the engine 14 is operating atthe low or idle power, the turf aerator 10 generally does not move andthe tine assembly 58 generally does not rotate such that an operatorcould potentially be struck by the moving turf aerator 10 or impacted bythe rotating tine assembly 58. This safety feature includes the treadle26, an engine governor 130 that is connected to the engine 14 and ablocking mechanism 140 that is mounted to the engine 14 and is inmechanical communication with the treadle 26. The operation of theengine governor 130, the components of the engine governor 130 and therelationship between the engine governor 130, the engine 14 and thethrottle lever 25 is generally understood by one having ordinary skillin the art and will not be described in detail.

Referring to FIGS. 6-7B, in the preferred embodiment, the engine 14 iscomprised of a thirteen horsepower (13 Hp) internal combustion enginebut is not so limited. The engine 14 is provided with fuel by a fueltank 14 a that is preferably mounted above the engine 14. The engine 14is also in communication with the throttle lever 25 and the governor 130to regulate its operation. The governor 130 includes a governoractuating arm 132 and a governor lever 134. The governor 130 includingthe actuating arm 132 and the governor lever 134 is movable to andbetween a biased position (not shown) and a loaded position (FIG. 7A).In the loaded position, the governor 130 regulates the engine 14 tooperate at idle or low power, as was described above.

The treadle 26 is pivotally mounted to the frame 12, preferably at ahinge 26 a, that permits pivoting of the treadle 26 between thedepressed position (dashed in FIG. 7) and an extended position (solid inFIG. 7). A first end 28 a of a treadle arm 28 is mounted to the treadle26 rearwardly of the hinge 26 a at a treadle lug 26 b. A second end 28 bof the treadle arm 28 is mounted to a pivoting bracket 29, which ispivotally mounted to the frame 12 at a bracket hinge 29 a. The pivotingbracket 29 includes a first leg 29 b and a second leg 29 c. The secondleg 29 c is mounted to the second end 28 b of the treadle arm 28 and thefirst leg 29 b is mounted to an actuating cable 27. The actuating cable27 extends from its attachment with the first leg 29 b, through aneyelet fixture 31 and is connected at an opposite end to the blockingmechanism 140. A spring 33 is mounted between the treadle lug 26 b andthe frame 12 and generally biases the treadle 26 to the extendedposition.

Referring to FIGS. 7-7B, the blocking mechanism 140 is preferablymounted to the engine 14 and is in communication with the actuatingcable 27 and the governor 130. The blocking mechanism 140 preferablyincludes a blocking bracket 141 with a first side 141 a and a generallyhollow tube 141 b at an opposite side, a spring member 142 that ismounted to the actuating cable 27 and an actuating shaft 143 that ismovably mounted within the hollow tube 141 b and is typically in facingcontact with a butt end 143 b of the governor lever 134 when the treadle26 is in the extended position. The blocking bracket 141 is preferablyconstructed of a generally rigid metallic material and is bolted orotherwise secured to the engine 14. The spring member 142 is secured atone end to the actuating cable 27 and includes a hook 142 a at anopposite end that is secured to a lug 143 a of the actuating shaft 143.The actuating shaft 143 is movably mounted to the hollow tube 141 b andis biased toward a blocking position by a spring 144. The actuatingshaft 143 is movable to and between the blocking position and anoperating position relative to the hollow tube 141 b. When the actuatingshaft 143 is in its operating position, the butt end 143 b may not be incontact with the governor lever 134 and the governor lever 134 and thegovernor actuating arm 132 generally operate in a conventional manner.The blocking mechanism 140 is not limited to the above-describedstructure and may be comprised of nearly any structure that is able tomanipulate the governor 130 in a below-described manner to provide asafety measure for the turf aerator in the typical operating conditionsof the turf aerator 10.

Referring to FIGS. 6-7B, in operation, the engine 14 is started by anoperator and the treadle 26 is in the extended position. In the extendedposition, the actuating shaft 143 is in the blocking position andcontacts the governor lever 134 to urge the governor lever 134 to theloaded position. As was described above, when the governor lever 134 isin the loaded position, the engine 14 operates at an idle or low power.Accordingly, even if the operator urges the throttle lever 25 to a highspeed, the governor 130 directs the engine 14 to operate at the idle orlow power. To utilize the turf aerator, the operator stands on thetreadle 26 or otherwise moves the treadle 26 from the extended positionto the depressed position. The operator applies a force to the treadle26 such that the biasing force of the spring 33 connected to the frame12 and the treadle lug 26 b is overcome to move the treadle 26 from theextended position to the depressed position. This movement of thetreadle 26 moves the treadle arm 28 in a downward direction, therebycausing the pivoting bracket 29 to pivot about the bracket hinge 29 aurging the actuating cable 27 through the eyelet fixture 31 toward theoperator or away from the engine 14. The actuating cable 27 urges theactuating shaft 143 from the blocking position to the operating positionagainst the bias of the spring 144. In the operating position of theactuating shaft 143, the governor lever 134 is able to move to itsbiased position. In the biased position, the governor 130 generallypermits the throttle lever 25 to control the power lever and operationof the engine 14 in a typical manner. In contrast, the biasing of thegovernor 130 to the loaded position when the actuating shaft 143 is inthe blocking position permits the engine to preferably run at only theidle or low power. As one having ordinary skill in the art willunderstand, the engine 14, governor 130 and throttle lever 25 operate ina typical manner for a small engine when the actuating shaft 143 is inthe operating position. When the treadle 26 is depressed and the engine14, governor 130 and throttle lever 25 are operating in their typicaloperating manners, the engine 14 is able to power the driven wheels 16and the tine assembly 58 to aerate a surface that the turf aerator 10moves along.

Referring to FIGS. 1-4, a pair of operating handles 30, 32 is pivotallymounted on the frame 12 and is operatively connected to a left hydraulicpump 34 and a right hydraulic pump 36 by control links 50, 52,respectively. The internal combustion engine 14 is provided with anoutput shaft 38 having a pair of pulleys 40 mounted thereon. Rotation ofthe drive shrift 38 is imparted to the left and right hydraulic pumps34, 36 by means of respective belts 42, 44, which are entrained aboutpulleys 46, 48 of the left and right hydraulic pumps 34, 36. The controllinks 50, 52 are connected to the respective control handles 30, 32 atone end thereof. The opposite ends of the control links 50, 52 areoperatively connected to the hydraulic pumps 34, 36, respectively, oneof the connections being shown in FIG. 1. Thus, the output and pressureof the hydraulic fluid from the left and right hydraulic pumps 34, 36 toleft and right hydraulic motors 54, 56 may be varied to vary the speedof the hydraulic motors 54, 56. The details of such hydraulic pumps 34,36 and hydraulic motors 54, 56 are well known in the art and are notdescribed in further detail.

The left hydraulic motor 54 and the right hydraulic motor 56 are mountedon the frame 12 above a tine assembly 58, as best seen in FIG. 3. A pairof sprocket wheels 60, 62 is mounted on an output shaft of the lefthydraulic motor 54 and a pair of sprocket wheels 64, 66 is mounted on anoutput shaft of the right hydraulic motor 56. The drive wheels 16 areeach provided with a sprocket wheel 68, 70. A chain 72 is entrainedabout the sprocket wheel 62 on the output shaft of the left hydraulicmotor 54 and the sprocket wheel 70 on the left drive wheel 16, as viewedin FIG. 3. A chain 74 is also entrained about the sprocket wheel 66 onthe drive shaft of the right side hydraulic motor 56 and the sprocketwheel 68 on the right drive wheel 16, as viewed in FIG. 3. Thus thedrive wheels 16 are driven by the left and right hydraulic motors 54,56.

The tine assembly 58, as best seen in FIGS. 2 and 4, is comprised of atransverse frame 76 having four depending supports 78, 80, 87, and 84. Afirst shaft 86 is rotatably mounted between the dependent supports 78,80 and a pair of conventional tine assemblies 88, 90 is connected to theshaft 86 for rotation therewith. A sprocket wheel 92 is also mounted onthe shaft 86 and is driven by a chain 93, which is in turn driven by asprocket wheel (not shown) on a shaft 95, which is driven by a chain 94and the sprocket wheel 60, which is driven by the left side hydraulicmotor 54. A second shaft 96 is mounted for rotation between the supports87, 84 and a pair of conventional tine assemblies 98, 100 is mounted onthe shaft 96 for rotation therewith. A sprocket wheel 102 is alsomounted on the shaft 96 and is driven by a chain and sprocket wheel (notshown) on a shaft (not shown) similar to the shaft 95 which is driventhrough a chain 104 trained about the sprocket wheel 64, which is drivenby the right side hydraulic motor 56. A third shaft 106 is rotatablymounted between the supports 80, 87 and a pair of tine assemblies 108,110 is rotatably mounted on the shaft 106 independently of each other.The third shaft 106 is not driven and, accordingly, the tine assemblies108, 110 simply free wheel and receive their rotation by contact withthe ground as the turf aerator 10 moves along the ground. The left andright shafts 86, 96 may be selectively or simultaneously rotated by theleft and right hydraulic motors 54, 56 under the control of the levers30, 32. As a result, the rotation of the left and right shafts 86, 96and the conventional tine assemblies 88, 90, 98, 100 may be convenientlyselected to assist the operator in turning the turf aerator 10 ortraversing a slope with the turf aerator 10.

Referring to FIG. 5, hydraulic circuitry interconnects the left andright hydraulic motors 54, 56 to the left and right hydraulic pumps 34,36. In addition to the hydraulic motors 54, 56 and the hydraulic pumps34, 36, a reservoir tank 120, a filter 122 and a control valve 124 areprovided. In addition to controlling the hydraulic pumps 34, 36 andhydraulic motors 54, 56, the control valve 124 also controls a cylinder126.

It will be appreciated by those skilled in the art that changes could bemade to the embodiment described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiment disclosed but isintended to cover modifications within the spirit and scope of thepresent invention, as defined by the appended claims.

1. A safety mechanism for a turf aerator with a frame and an engine witha governor that generally prevents the turf aerator from operating atfull power unless the safety mechanism is engaged, the safety mechanismcomprising: a blocking mechanism mounted to the frame; a manualactuation device mounted to the frame and in mechanical communicationwith the blocking mechanism, the blocking mechanism urging the governortoward a loaded position, the engine operating at a generally low powerwhen the governor is in the loaded position.
 2. The safety mechanism ofclaim 1 wherein the blocking mechanism includes an actuating shaft thatis biased toward a blocking position, the actuating shaft being infacing engagement with a governor lever in the blocking position,thereby urging the governor to the loaded position.
 3. The safetymechanism of claim 1 further comprising: a platform mounted to a firstside of the frame; and a tine assembly mounted to an opposite side ofthe frame from the first side, wherein the manual actuation device ismounted to the frame proximate the first side such that an operator isable to manipulate the manual actuation device while standing on theplatform.
 4. The safety mechanism of claim 3 wherein the manualactuation device is comprised of a treadle that is pivotally mounted tothe frame proximate the platform.
 5. The safety mechanism of claim 4wherein the treadle is mounted to a treadle arm, the treadle arm mountedto a pivoting bracket, the pivoting bracket mounted to an actuatingcable, the actuating cable mounted to the blocking mechanism such thatthe blocking mechanism may be actuated by manipulation of the treadle.6. The safety mechanism of claim 1 wherein the blocking mechanismincludes an actuating shaft that is movable to and between a blockingposition and an operating position, the actuating shaft being biasedtoward the blocking position.
 7. The safety mechanism of claim 6 whereinthe actuating shaft is biased toward the blocking position by a spring.8. The safety mechanism of claim 6 wherein the actuating shaft isslidably mounted to the engine within a hollow tube of a blockingbracket.
 9. The safety mechanism of claim 1 further comprising: athrottle lever mounted to the frame, the throttle lever providing anoperator control for the power of the engine, the throttle lever andgovernor operating together to set the operating power of the engine.